Nest Thermostat Downgrade Back to Honeywell, [ISSUES]

Old 05-06-14, 09:19 PM
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Nest Thermostat Downgrade Back to Honeywell

Hey everyone!

First post here, I did a search but could not find a topic that would match my situation. I've been looking on the net and reading the manuals for my thermostat but I cannot get it to work properly.

I'll try to give as much information as I can and describe the problem in detail.

-Honeywell Model TH2210D1007 2H/1C

I had a Nest installed and am downgrading back to the original Honeywell. Upon re-wiring the Honeywell the following problems occur-

1. A few (5-10) seconds after I re-connect the Honeywell the furnace fan turns on even though the thermostat is set to [OFF] and fan is set to [AUTO]

2. When the furnace fan turns on, warm/hot air blows out and Honeywell switches seem to not have any effect on the furnace/condenser

If I cut the power to the furnace + condenser then re-wire the Nest, I have full control and can turn Cool [ON/OFF] at will and furnace doesn't turn on automatically.

Below is how I re-wired the Honeywell-

Y- Yellow
R- Red
C- Blue
G- Green
O/B- Orange
Aux/E- White

Here is how I wired the Nest-

Y1- Yellow
G- Green
O/B- Orange
Rh- Red
W1- White
W2/Aux- [EMPTY]
C- Blue

One of the topics I found online suggested reversing the O/B and W. This sort of worked because now the furnace fan didn't turn on as soon as I plugged in the Honeywell. It gave me control of the system but did not blow cold air when set to [COOL].

I tried to look up instructions on how to reset the Honeywell but was unsuccessful. A similar Honeywell model said putting in the batteries backwards would reset it but it did not work for me.

The A/C system seems to be working fine and not malfunctioning as it works perfectly with the Nest. It is almost as if there is a problem with the wiring for the Honeywell or the Honeywell itself.

I'm open to suggestions!

Thank you in advance for any replies and views!

Old 05-06-14, 09:47 PM
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Sounds like programming issue. Hold both up and down temp controls for at least 10 seconds. LCD will change. 1rst flashing set point is heat pump operation. I believe it will pop up a big number (1) and down in corner a small zero. Hit set button to change zero to 1. You can then go thru the rest of set up or just reframe from touching after time out it should return to home screen. Do this with tstat in ac mode. A lot of these tstats have a slide switch on back for gas/electrical or heat pump operation. You do know you have a heat pump correct. It's a heater that cools also. In normal op mode it is in heating mode. Tstat calls for ac it energizes y & o. Y being 24 volt outside coil. O being power to reversing valve. This valve reverses flow of refrigerant and allows cooling. Tstat is not communicating with O. You are calling for ac but reversing valve has no power applied. Long gone are the days of good ol mercury stats. As long as well leveled they worked to well to long.
Old 05-07-14, 07:20 AM
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I was reading in your post for the reason you were going away from the Nest but, unless I missed it, I didn't see one. Why are you switching back, if you don't mind my asking?
Old 05-07-14, 05:22 PM
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Hey guys,

Thanks for your replies!


I went through the programming sequence as outlined in the Honeywell manual. The 1[SUB]0[/SUB] is for Fahrenheit and the 1[SUB]1[/SUB] is for Celsius.

The 3[SUB]x[/SUB] Heating Cycles Per Hour function setting is what changes the operating mode.

-3[SUB]2[/SUB]: 30 mins (steam, gravity)
-3[SUB]3[/SUB]: 20 mins (hot water)
-3[SUB]4[/SUB]: 15 mins (gas, oil)
-3[SUB]5[/SUB]: 12 mins (gas, oil)
-3[SUB]6[/SUB]: 10 mins (electric) (current setting)

You mentioned setting the heat pump setting with the tstat in AC mode. Do you mean while it is docked to the wall or with the tstat switch set to [COOL]?

You also mentioned the tstat is not communicating through the O (orange right?) wire to activate the valve. Could it be a problem with the tstat's O contact? The Nest isn't having this problem as noted.

I'm looking forward to your reply!


I'm switching back because I am moving to a different apartment and do not want to leave my Nest there as I plan on using it at my new place.

Thanks in advance,

Old 05-08-14, 05:07 PM
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I wouldnt call going from Nest back to regular stat a downgrade, more like an upgrade.
I think peole would find if they just set their thermostat in one basic place and leave it alone, their bills will be cheaper and your equipment will be happier.
Old 05-08-14, 05:59 PM
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If you remove the stat and look at the batteries, do you see a toggle switch?
Is it set for gas/oil or electric/heat pump ?

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